Cord blood testing

[DIANA RAMIREZ]

Our P & P states: " Testing will be performed on cord blood samples as ordered. An antibody Screen and Quick Screen (A1 cells and B cells tested with the patient's plasma/serum at the antiglobulin phase) will be performed on all samples with a positive direct antiglobulin test (DAT) if the Quick Screen does not demonstrate an antibody that would explain the positive DAT perform an elution.

We usually could explain the DAT positive if Mother ABO is incompatible with the baby performing a "Quick Screen". We received a suggestion for others Blood Bankers to eliminate the Quick Screen and perfom Lui Easy Freeze Elution on ALL samples with DAT positive.

What are you doing with Cord Blood samples with DAT positives? Quick Screens and Lui as needed? or Lui Easy Freeze Elution on all samples?

[profbaud]

We do a Forward blood type on all infants from group O moms and Rh neg moms. If the Mom has a negative Antibody screen and if the baby is an A or B born to an O mom, then we just do an IAT on A or B reverse cells. That determines if Mom's Anti-A, Anti-B or Anti-A,B has crossed the placenta. A Lui freeze is outdated.

[Yanxia]

We do a Forward blood type on all infants from group O moms and Rh neg moms. If the Mom has a negative Antibody screen and if the baby is an A or B born to an O mom, then we just do an IAT on A or B reverse cells. That determines if Mom's Anti-A, Anti-B or Anti-A,B has crossed the placenta. A Lui freeze is outdated.

I don't agree with you.Mom's anti-A,anti-B or anti-AB can bound on the cells and the DAT is negative. We will do hot elution in this condition.

[vav5325]

In our facility we perform Lui freeze on newborns with positive DATs (mom has negative screen l). Though I've heard from other new techs that the procedure is quite outdated. I wouldn't mind knowing as well what other facilities are doing in this situation.

[swede]

If the baby is A or B and the mom is O with a negative Ab screen, we simply report "Mom is type O, her Ab screen is negative, this is a probable ABO incompatibility." The docs came up with this years and years ago, and they are still content with the report. If we need to do an eluate of any kind, we use Immucor Elu kit and run it against panel cells and A and B cells. We perform our eluates in Gel, so they do not require much sample.

[L106]

If the baby with a Positive Direct Antiglobulin Test is Group A, B, or AB and mother is not known to have an unexpected antibody, we perform a Lui Freeze Thaw Elution. We in Blood Bank recognize that it is most likely an ABO incompatibility and not the most efficient use of our time, but our Nursery docs want the cause of the Pos DAT identified, and the Lui is an easy (and cheap) procedure.

I would like to hear how others are handling this issue, too. Also, what makes a procedure "outdated?"

[David Saikin]

I still do Lui's when the Mom is an O and the baby is not and the MOM has a negative ab screen and the baby a +DAT. It's inexpensive and easy.

[Mary**]

We don't do an eluate on cords unless it its ordered, which almost never happens. Our docs just "treat" the baby.

[Malcolm Needs ☆]

Also, what makes a procedure "outdated?"

[Malcolm Needs ☆]

We don't do an eluate on cords unless it its ordered, which almost never happens. Our docs just "treat" the baby.

What???????????

You mean the doctors treat the symptoms and not the laboratory findings?

Surely, this is almost unheard of these days!

:rolleyes::rolleyes:

Good for your doctors.

:D:D:D

[mcgouc]

We don't do an eluate on cords unless it its ordered, which almost never happens. Our docs just "treat" the baby.

We switched to this policy a couple of years ago and had the same results. We get and keep all the cords 10 days. If the mom is group O, Rh negative or has a clinically significant antibody, we routinely do the DAT on the cord. If the mom is Rh negative we also do the ABO/Rh on the cord. At first they would order an elution if an O negative mom had an anti-D probably caused by RhIG and the baby was an A or B positive with a positive DAT. They ordered a few of those elutions and then decided it didn't affect how they treated the baby so they stopped ordering them. They have ordered DATs a few times on cords of jaundiced babies who don't meet our routine criteria. There have been no complaints since we started this policy and the techs really like it. :)

[csjuarez]

In our hospital cord blood ABO/RH type and DAT are ordered when the mother is type O or Rh negative. If the DAT is positive we do elution ONLY if the positive DAT cannot be explained by the mother's serology. If the mother is group O and the baby is non-group O, that explains it. If the mother has a positive antibody screen, that explains it. So it's only if the baby is type-compatible with the mother and the mother's antibody screen is negative that we do an elution, which is in essence almost never. When we do an elution we use the Immucor Elu-Kit and test with screening cells and A1& B cells. This is most often negative since the most likely reason for the positive DAT in this scenario is an antibody to a low incidence antigen inherited from the father and if it didn't show up in the mother's antibody screen it is unlikely to do so in the baby's eluate since it's probably not present on the screening cells. Our neonatologists treat on the clinical basis, too, and the exact ID of the cause of the positive DAT is of only academic interest in most cases.

[AMcCord]

We do ABO/Rh and DAT on babies of Rh neg mothers and for O mothers from one family practice in town (no, not ordered by the older docs but one of the new ones who had a mentor who is behind the times!). If mom is O with a negative antibody screen and baby is not O, we add an antibody screen, including A and B cells. If positive with the A or B cells and negative with screen cells, we report 'Immune anti-A pos' or whatever. If mother is known (by us) to have a positive antibody screen and we can get our hands on a specimen from baby, we will do ABO/Rh, and DAT, and screen, but no elution. Mom's antibody is presumed to be the reason for the pos DAT. However, they won't necessarily collect a cord blood specimen. The docs worry a great deal about the antibody prior to birth, but once the baby is born it seems to disappear from their radar, so BB worries for them. We do an elution if the DAT is positive and we can't explain it with ABO differences or a known antibody (almost never needed). OR we do an elution if the doc orders it (never happens). This has been our policy for many many years and we don't get any grumbles.

Edited October 19, 2009 by AMcCord

[PHYLLIS]

How do you profiency test your LUIs?

[L106]

Twice a year we do (and document, or course) a "Clinical Correlation Study" as an "alternative method" to satisfy the proficiency testing. We take a case where a Lui elution was performed and do a retrorespective review of the case. We document the basic date of the baby's ABO/Rh and DAT results, mother's ABO/Rh and Antibody Screen results, test results of the Lui Elution, and investigate pertinent lab data (serial bilirubins, reticulocyte count, etc.) and clinical data (evidence of jaundice, etc) to evaluate if the Lui Elution results "make sense."

As Phyllis, I am also interested in how others do proficiency testing for Lui Elutions.

[BBK710]

If the baby is A or B with a postive DAT and the mom is O with a negative antibody screen we report "presumtive evidence of ABO incompatibility. We have never been asked to do an elution and we have been doing it this way for over 10 years.

[Bill]

AMcCord & BBK710--you realized you jinxed yourselves by saying "we never!!"

[AMcCord]

Thanks Bill! If I had remained blissfully ignorant of that, it still woulldn't have counted. Now you went and called my attention to it! I'm sure it'll happen in the middle of the night with an inexperienced tech and who knows what will happen then!!!

[Deny Morlino]

Yes the infamous "Murphy" of Murphy's law does tend to sit on my shoulder or ride shotgun frequently. I will assume others have the same curse?

[GilTphoto]

We only do a forward ABO/Rh and DAT with IgG only on all cords. The report also includes the mother's ABO/Rh.

If the mother is type O and the baby is not, and the baby's DAT is positive, ABO incompatibility is assumed and the doctor will monitor the bilirubin. There is no reason to prove the presence of anti-AB. The only thing that matters is the bilirubin. Most bilirubin increases takes a few days, but rarely require anything other than more time under the bili light.

If the mother has an antibody that causes HDN, we will phenotype the baby if Rh antibody, or do Gamma Elu-KIt if other antibodies (since you can't do phenotyping if DAT is positive). If ABO is also a possibility, we will also do Lui Freeze/Thaw with A1 and B cells. Someone above mentioned doing A1 and B cells with Gamma Elu-KIt. This is not a good method for ABO.

We had a type B baby with Fy(a), Jk(a) and anti-B in eluate a few days ago. The mother also had an anti-M. The baby was discharged with a 7 total bili on day 3.

[bbbirder]

I have never had a doctor order an elution. I don't think 99% know what one is. (And, no, I don't think I jinxed myself by saying never!)

For cords with positive DATs we do a standard antibody screen plus A and B cells on the cord serum. That answers the question most of the time. If not, we start testing mom's specimen. We rarely do an elution (and if needed we will use the Elu-Kit).

[Malcolm Needs ☆]

I have never had a doctor order an elution. I don't think 99% know what one is. QUOTE]

Oh boy, do I agree with that sentiment!

:eek::eek:

[rravkin@aol.com]

What???????????

You mean the doctors treat the symptoms and not the laboratory findings?

Surely, this is almost unheard of these days!

:rolleyes::rolleyes:

Good for your doctors.

:D:D:D

Very good Malcolm! :)

[BBK710]

Thanks Bill! If I had remained blissfully ignorant of that, it still woulldn't have counted. Now you went and called my attention to it! I'm sure it'll happen in the middle of the night with an inexperienced tech and who knows what will happen then!!!

I couldn't agree more. Don't know what I was thinking. I try very hard not to ever say NEVER.

[adiescast]

Yes the infamous "Murphy" of Murphy's law does tend to sit on my shoulder or ride shotgun frequently. I will assume others have the same curse?

Absolutely! I really am not superstitious anywhere but at work!